DMcG. Having read Hansard I think I would need a legal background to fully understand all the ramifications. As far as I can make out when it comes to rights we default to those established by international agreements and existing British case law. I find it hard to define which would be the superior condition. Time alone will tell.
This is not meant to be an evasive answer, but the subject simply does not lead to yes no answers. Perhaps the existing legislation is more beneficial, perhaps not. Then again only a naive idealist would believe that no negatives are attached to brexit.